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Hi GMT439 We used incandescent bulbs for everything as my wife hated the light from the old curly fluorescent bulbs CFL. The LEDs are nicer and safer then those CFLs, but I agree the LED spectrum is blue and washed out. The LEDs are more energy efficient and make less heat, but we still have and prefer filament bulbs in a few places.

​@@n3sdoham322just did some testing on a Future Lumen bulb and thought I'd see if anything came up on the internet. Sure enough here you are! Wasn't the same failure on mine, flickering yes, however, I took off the dome and tested the bridge rectifier to find it faulty. Bummer.

Hi Quangmi3402, There is a calibration of amplitude factor that can be changed under settings, and this will compensate for different sound card variations. I tried to duplicate your results, and I am getting Vp-p=46.02m with Vf of 16.27m, which does not match your measurements. I'm not sure what the program is doing here. I am using internal signal generator at SINE, 400hz, and amplitude of .023, with calibration value set to 1.0 v/div. Vrms of 775mv should equal 2.192 vp-p It appears in my setup the Internal Signal generator amplitude is .5x of Vp-p with calibration set to 1v/div. and using a different cal of 1.414 v/div, now the generator output is scaled to RMS, Gen chan 1 amplitude 1.0 and the scope reads p-p 2.828, and veff 1.0 which the math works correctly in my setup. You input .775 rms according to your meter, which should have read 2.192 Vp-p, but your only got Vp-p .046. I would calculate a calibration value of 47.65 v/div to compensate for your sound card. I would also think you would want an external attenuator or volume control to reduce the input signal to avoid clipping on the sound card input, and scale your calibration value accordingly. Let me know what your results are. Good luck and happy experimenting.

Hi SpinStar, sorry for the delay in response. I am aware of the CPU on the boards. Hamtronics never released the source for these chips to my knowledge after the owner passed away. The PLL synthesizer frequency controller U2 is a serial controlled device to steer the frequency of the master oscillator. If the CPU is zapped, the PLL won't get programmed, and I suspect the Master Oscillator will just sit at 143mhz, or so depending on the slug tuning. I'm unaware of anybody who has the code to generate a replacement CPU. Its a Moto 68HC705 or MC9S08PA4 according to the schematic, which in checking DigiKey, I'm seeing that this chips are Obsolete, zero stock, but Mouser has a few. These are internal rom/prom one time programmable CPUs. In theory a replacement CPU of another family could be programmed to make the serial stream to the PLL, which I expect only needs to be setup once on power up or reset to set the internal divider registers. I have done repairs on a number of ham systems that have failed over the years. Hamtronics, spectrum, maggiorie, tend to blow the 5v or 8v regulator first, then the 12v transistors tend to be the culprits after the V-regs. In particular the smaller transistors, oscillators, multipliers and pre-drivers tend to be the weakest links. I've met Kevin from Repeater-Builder at one of the club meetings in Butler PA. The Repeater-Builder guys are a good group of hams providing into for keeping the old gear still running!

@@n3sdoham322 well it sounds like the Hamtronics guy was a brilliant engineer especially given the timeframe. I believe the REP - 200 uses a 6803 Motorola Micro computer. So I may be able to disassemble some of the macro code and I do not think that it controls any PLL functions as you described. With this being the case if my frustration level even gets up by a slight amount I will simply create a new micro controller to run the transmitter and receiver. I do want to thank you for taking the time to respond and the information and also the reference to repeater-builder as I have been using some of their technical references so far. If I find out anything definitive or get somewhere, I will get back with you just to let you know how things worked out. We certainly don’t want the repeater system to die or lose the repeater pair as some of the nearby big cities would be more than happy to suck them up even though they have a pile! Thanks again and 73…

@@SpinStar1956 I was on the wrong page, I'm thinking the radio modules, and not the controller. I've no experience with any of the Hamtronics controllers. Sadly, many of the controller manufacturers are out of business. CAT,ACC,NHRC... One of my favorites, MCC Micro Computer Concepts still appears to be in business, and Ron makes a dandy little controller, RC-100. N9EE his website link, www.mccrpt.com links to face book. I also have used ALLSTAR PC software controller using a RIM Repeater interface module and running linux. Best wishes in reviving the controller!

@@n3sdoham322 Well thank you. I still found your video dealing with the RF section very interesting. I’ll just have to see what happens but appreciate your help. 73…

Hi James. Perhaps, but I did not find a normalization function in the software I was using.

@@n3sdoham322 looks interesting product anyway

Hi James. I believe I did measure the coax. Let me check my notebook and will post.

@@n3sdoham322 <3

​@@jbx907 I realized I put my notes in a bag and included them with the duplexer. But you were not the first to ask this question, so I'll repost my old answer: I have a couple of the old cables with the N connectors still intact. Overall they measure 27cm from tip to tip of the N connector. With 20 cm of Rf 142 coax visible between the connectors. I estimate 24.2 cm of coax dielectric including what is inside the neck of the N connector. The interconnect cables between the duplexer and the Repeater are approx 50cm in length, and trying longer / shorter, did not seem to effect the isolation noticeably. There is a N Female mounted to the triangle plate with 2 cables exiting it. I could not locate a replacement, so I took it apart and cleaned it well, removed the old cables and reused it with no problems. If you read other comments I responded to, the length is close to 1/2 wavelength in coax at 66% velocity, but trying longer or shorter ones did not effect my tuning or loss significantly. 144/220 duplexers, the coax length will skew the notch frequency up or down.

@@n3sdoham322 i got this duplexer with a rg8 size pigtail the didn't look original in length, it was very hard to tune, i changed with an different rg142 pigtail and the tuning seemed to change and improve, i knew it was the pigtail causing it. thank you very much. so you would approximate 1/2 wavelength of freq of operation x VF, are all rg142 66%? i have problems in getting the notches aligned to form a single deep dip with random pigtails, it has to be pigtails that s causing it, even on the pass band has two humps that wont align perfectly. thank you again, ill try making these pigtails, i for got, my duplexer only has one port each can, i am a subscriber and you have cool videos, thank you again

Hi Robert. Excellent suggestion! I have a flex gooseneck around here somewhere... thanks for the idea!

Hi Mario, Sounds like in interesting application, but I did not write the software so I can't add the modifications your request. The software was written by Christian Zeitnitz, his website is www.zeitnitz.eu. He has contact info on his website and might be able to do what you ask. What I will suggest is to see if you can use the stereo frequency generators to create a tone in headphones from oscillator A and drive an LED strobe with the same pitch using Oscillator B, and have the patient sing a matching or near matching note with the headphones while using what I would describe as a dental mirror with the strobe LED on the end of the dental mirror. You probably have specialized tools for this, but thats my best idea at the moment.

Humm... TSP.?! XYL has some of that. I have some 220 cans that need some help. May try some externally on the screws. Thanks for the idea.

I used to water wash PCBs after SMT chip rework with water soluble flux back in the 90's. Yep, drying was the key.

No oil, but definately a powerful magic spell!

Ivan, I have a couple of the old cables with the N connectors still intact. Overall they measure 27cm from tip to tip of the N connector. With 20 cm of Rf 142 coax visible between the connectors. I estimate 24.2 cm of coax dielectric including what is inside the neck of the N connector. The interconnect cables between the duplexer and the Repeater are approx 50cm in length, and trying longer / shorter, did not seem to effect the isolation noticeably.

Got me thinking... 444.250 / 449.250. I was trying to calculate the length of the coax, in terms of wavelength including the velocity.... They are near halfwave length coax. 150/f * .695 (velocity of Rg142) and I get 23.4 cm. The coax is a .9 cm longer at 24.2 cm. So I am not sure exactly how this length is calculated, or if its supercritical that they be exactly 1/2 wl, or if close enough will do.

I have had best success tuning duplexers using the coax that is going to be used with the transmitter and RX. Marking which one went were with tape or a permanent marker pen. Best wishes!

@@edbathgate5680 Thank you very much E. I bought this used duplexer from a person who wanted to know what it was about, LOL. it came with just one cable that has exactly that measurement that you said. Duplexers typically use 1/4 wave between the cavities. isnt it? I calculated, it wouldn't work, the distance between the connectors is much greater. so I started looking on the internet and found you here.

@@edbathgate5680 this result of approximately 1/2 wave was what I also got next. taking into account that it has the distance to the loop etc ... I was a little lost. I saw in an old WACON advertisement the recommendation to respect the cable measurements and not modify them. But I didn't get to do tests with different measures to see the behavior with different measures. I think I will do that later

where did you get the winnwt4 software?

@@physics18bravo Hi Luis, I don't recall just where I downloaded it from. I think I found a link on a ham radio group.